How close is nuclear fusion power?

today i want to talk about nuclear fusion i've been struggling with this video for some while this is because i'm really supportive of nuclear fusion research and development however the potential benefits of current research on nuclear fusion have been incorrectly communicated for a long time scientists are confusing the public and policy makers in a way that makes their research appear more promising than it really is and that's what we'll talk about today before we talk about nuclear fusion let me tell you a little about our sponsor magellan tv magellan tv is a streaming service for science and nature documentaries they have more than 3 000 documentaries on science and science related topics and they're adding new ones each week if you like this video you may for example also like their documentary the story of energy in which you learn what energy is why it is so important for the growth of civilization and what energy has to do with entropy you will also get to see a nuclear fusion reactor and all of this in 4k i have watched quite a few of their documentaries and i have found them to be really interesting and well done magellan tv is also super easy to use and runs on pretty much any device if you want to try it out use the link below because that way you will get a full month free now let's talk about nuclear fusion there's a lot to say about nuclear fusion but today i want to focus on its most important aspect how much energy goes into a fusion reactor and how much comes out scientists quantify this with the energy gain that's the ratio of what comes out over what goes in and is usually denoted q if the energy gain is larger than 1 you create net energy the point where q reaches 1 is called break even the record for energy gain was just recently broken you may have seen the headlines an experiment at the national ignition facility in the united states reported they'd managed to get out 70 percent of the energy they put in so a queue of 0.7 the previous record was 0.67 it was set in 1997 by the joined european taurus jet for short the most prominent fusion experiment that's currently being built is ita you will find plenty of articles repeating that eta when completed will produce 10 times as much energy as goes in so a gain of 10. here is an example from a 2019 article in the guardian by philip ball who writes the eater project hopes to conduct its first experimental runs in 2025 and eventually to produce 500 megawatts of power 10 times as much as is needed to operate it here is another example from science magazine where you can read eta is predicted to produce at least 500 megawatts of power from a 50 megawatt input so this looks like we're really close to actually getting energy from fusion right no wrong remember that nuclear fusion is the process by which the sun creates power the sun forces nuclei into each other with the gravitational force created by its huge mass we can't do this on earth so we have to find some other way the currently most widely used technology for nuclear fusion is heating the fuel in strong magnetic fields until it becomes a plasma the temperature that must be reached is about 150 million kelvin the other popular option is shooting a fuel pallet with lasers there are some other methods but they haven't gotten very far in research and development the confusion which you find in pretty much all popular science writing about nuclear fusion is that the energy gain which they quote is that for the energy that goes into the plasma and comes out of the plasma in the technical literature this quantity is normally not just called q but more specifically q plasma this is not the ratio of the entire energy that comes out of the fusion reactor over that which goes into the reactor which we can call q total if you want to build a power plant and that's what we're after in the end it's the q total that matters not the q plasma here's the problem fusion reactors take a lot of energy to run and most of that energy never goes into the plasma if you keep the plasma confined with the magnetic field in a vacuum you need to run giant magnets and cool them and maintain that and pumping a laser isn't energy efficient either these energies never appear in the energy gain that is normally quoted the q plasma also doesn't take into account that if you want to operate a power plant the heat that is created by the plasma would still have to be converted into electric energy and that can only be done with a limited efficiency optimistically maybe 50 percent as a consequence the q total is much lower than the q plasma if you didn't know this you're not alone i didn't know this until a few years ago either how can such a confusion even happen i mean this isn't rocket science the total energy that goes into the reactor is more than the energy that goes into the plasma and yet science writers and journalists constantly get this wrong they get the most basic fact wrong on a matter that affects tens of billions of research funding it's not like we're the first to point out that this is a problem i want to read you some words from a 1988 report from the european parliament more specifically from the committee for scientific and technological options assessment they were tasked with establishing criteria for the assessment of european fusion research in 1988 they already warned explicitly of this very misunderstanding the use of the term break-even as defining the present program to achieve an energy balance in the hydrogen deuterium plasma reaction is open to misunderstanding in our view break even should be used as descriptive of the stage when there is an energy break even in the system as a whole it is this achievement which will open the way for fusion power to be used for electricity generation they then point out the risk in our view the correct scientific criterion must dominate the program from the earliest stages the danger of not doing this could be that the entire program is dedicated to pursuing performance parameters which are simply not relevant to the eventual goal the result of doing this could in the very worst scenario be the enormous waste of resources on a program that is simply not scientifically feasible so where are we today well we're spending lots of money on increasing q plasma instead of increasing the relevant quantity q total how big is the difference let us look at eta as an example you have seen in the earlier quotes about eta that the energy input is normally said to be 50 megawatts but according to the head of the electrical engineering division of the eater project ivona benefatto eta will consume about 440 megawatts while it produces fusion power that gives us an estimate for the total energy that goes in though that is misleading already because 120 of those 440 megawatts are consumed whether or not there's any plasma in the reactor so using this number assumes the thing would be running permanently but okay let's leave this aside the plan is that eater will generate 500 megawatts of fusion power in heat if we assume a 50 efficiency for converting this heat into electricity eta will produce about 250 megawatts of electric power that gives us acute total of about 0.57 that's less than a tenth of the normally stated q plasma of 10. even optimistically eta will still consume roughly twice the power it generates what's with the earlier claim of the queue of 0.67 for the jet experiment same thing if you look at the total energy jet consumed more than 700 megawatts of electricity to get its 16 megawatts of fusion power that's heat not electric so if you again assume 50 efficiency in the heat to electricity conversion you get acute total of about 0.0 and not the claimed 0.67 and those recent headlines about the nif success same thing again it's the q plasma that is 0.7 that's calculated with the energy that the laser delivers to the plasma but how much energy do you need to fire the laser i don't know for sure but nif is a fairly old facility so a rough estimate would be 100 times as much if they'd upgrade their lasers maybe 10 times as much either way the q total for this experiment is almost certainly well below 0.1 of course the people who work on this some of them physicists some of them human know this distinction perfectly well but i can't shake off the feeling they quite like the confusion between the two cues here is for example a quote from hult camp who at the time was the project construction leader of ito he said in an interview in 2006 eta will be the first fusion reactor to create more energy than it uses scientists measure this in terms of a simple factor they call it q if eta meets all the scientific objectives it will create 10 times more energy than it is supplied with here is nick walkdown from jet in a ted talk referring to eta eater will produce 10 times the power out from fusion energy than we put into the machine now jet holds the record for fusion power um in 1997 it got 65 of the power out that we put in not one not 10 but still getting close but okay you may say no one expects accuracy in a ted talk then listen to it director general dr bijou speaking to the house of representatives in april 2016. and i look forward to learning more about the progress that eder has made under dr bigo's leadership to address previously identified management deficiencies and to establish a more reliable path forward for the project okay the heater will have been delivered is a okay full demonstration that we could have okay 500 megawatt coming out of the 50 mega what we are we will put in what are we to make of all this nuclear fusion power is a worthy research project it could have a huge payoff for the future of our civilization but we need to be smart about just what research to invest into because we have limited resources for this it is super important that we focus on the relevant question will it output energy into the grid there seem to be a lot of people in fusion research who want you to remain confused about just what the total energy gain is i only recently read a new book about nuclear fusion the star builders which does the same thing again only briefly mentions the total energy gain and never gives you a number this misinformation has to stop if you come across any popular science article or interview or video that does not clearly spell out what the total energy gain is please call them out on it thanks for watching see you next week

Channel: Sabine Hossenfelder

Views: 725,776

Keywords: fusion power, nuclear fusion, nuclear fusion breakthrough, how close is nuclear fusion power, nuclear fusion power, nuclear fusion break even, nuclear fusion power plant, ITER, fusion reactor, is nuclear fusion hype, hype, physics, nuclear physics, hossenfelder, science without the gobbledygook, JET, joint european torus, NIF fusion, tokamak, inertial confinement, fusion, energy, renewable energy, how close are we to fusion power, is nuclear fusion possible

Id: LJ4W1g-6JiY

Length: 12min 49sec (769 seconds)

Published: Sat Oct 02 2021

Reddit Comments

[u/BTRCguy]

We'll certainly have practical fusion reactors in fifty years. That's what they told me when I was a kid...fifty years ago.

[u/Enkaybee]

hopium is the real fuel for the future

[u/moon-worshiper]

There has been no energy gain for 40 years. In fact, it is taking more and more energy to try to sustain a fusion reaction. It is only a few minutes now, and it is taking a gigawatt of power to do that. Funny, gigawatt of power and still no time travel, much less sustained fusion.
https://earthsky.org/human-world/nuclear-fusion-ignition-triggered-lab/

[u/ufosandelves]

In this video Sabine explains the energy produced by current nuclear fusion experiments has been exaggerate because scientists do not include the energy it takes to run the equipment (like the giant magnets) when calculating the energy gain. They only use the energy that is put into the plasma which is a small amount of the total energy needed for the experiment. She suggests the energy gain is exaggerated to help funding of these projects. In short, nuclear fusion is not going to save us anytime soon if ever.

[u/MalcolmLinair]

I thought this was common knowledge. We've only recently been able to produce more energy than is consumed at all. The tech is decades away from being in a useful state, and will require either better fuel or more efficient containment mechanisms.

[u/2littletoolate2]

no shit gotta keep the hopium alive

btw make a submissive satement fast before u get deleted by autobot AI overlord

[u/[deleted]]

Fusions been 10 years out for the last 50 years.

[u/[deleted]]

Fusion is still the only realistic clean energy source I could see meeting our demands. If it leads nowhere, then we are totally out of hope.

[u/Ghostifier2k0]

Regardless of how difficult it may be we must continue this pursuit for alternative energy.

Renewables alone can't save us.